This application relates to and claims priority from Japanese Patent Application Nos. 10-320961 filed on Nov. 11, 1998 and 11-65344 filed on Mar. 11, 1999, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to a vehicle air conditioner, and particularly to an air conditioning unit of the vehicle air conditioner, in which a heat exchanger is disposed in a substantially horizontal direction, and air blown by a blower flows through the heat exchanger in a substantially vertical direction.
2. Related Art
U.S. Pat. No. 5,755,107 discloses a vehicle air conditioner having an air conditioning unit disposed in a passenger compartment of the vehicle. In the air conditioning unit, a cooling heat exchanger (evaporator) is disposed in a substantially horizontal direction, and a heating heat exchanger (heater core) is also disposed in a substantially horizontal direction at an upper side of the cooling heat exchanger. A blower is disposed on a side of the air conditioning unit in a vehicle width direction. As a result, a size of the air conditioning unit is reduced.
In the air conditioning unit, air blown by the blower flows into a space below the cooling heat exchanger in the substantially horizontal direction (i.e., vehicle width direction). Then, air changes a flow direction in the space, and flows upwardly through the cooling heat exchanger and the heating heat exchanger. After. a temperature of air is adjusted to a predetermined value by the cooling and heating heat exchangers, air is blown into the passenger compartment.
In the air conditioner, an air duct does not need to be disposed on a front or rear side of the air conditioning unit, thereby reducing a size of the air conditioning unit in a vehicle front-rear direction. Further, since both the cooling and heating heat exchangers are disposed respectively in the substantially horizontal direction, a size of the air conditioning unit in a vehicle up-down direction is also reduced.
However, in the above-mentioned air conditioning unit, foot ducts through which air is blown toward foot portions of passengers in the passenger compartment are disposed on both right and left side surfaces of a case of the air conditioning unit so that air is blown toward the foot portions of both a driver and a front passenger. Therefore, a size of the air conditioning unit is increased by a size of the right and left foot ducts in the vehicle width direction. As a result, a space for accommodating the foot portions of the driver and the front passenger (hereinafter referred to as foot accommodating space) in the passenger compartment is reduced by the foot ducts. Especially in the foot accommodating space of the driver, it becomes difficult to secure both a space for accommodating operation pedals such as an accelerator pedal and a brake pedal and a space for accommodating the air conditioning unit.
JP-A-9-188123 also discloses a vehicle air conditioner having an air conditioning unit in which a heat exchanger is disposed in a substantially horizontal direction. However, since a blower unit is disposed on a vehicle front side of a case of the air conditioning unit, a size of the air conditioner in a vehicle front-rear direction is increased. As a result, it becomes difficult to mount the air conditioner on an instrumental panel in a passenger compartment.
Further, in the air conditioner, a foot opening is disposed at a vehicle rear portion of the case, and air is blown toward a foot portion of a passenger through the foot opening in a foot mode. Generally, warm air needs to be blown especially to a portion from an ankle to a toe of the foot portion of the passenger to improve heating feeling. However, the foot opening is disposed at the vehicle rear portion of the case and is far away from the toe of the passenger. Therefore, it is difficult to blow warm air directly to the toe of the passenger, or an additional long foot duct extending from the foot opening to the toe of the passenger is required.
Further, in both U.S. Pat. No. 5,755,107 and JP-A-9-188123, a separation point where air from the foot opening is blown separately to vehicle right and left sides is disposed at a downstream air side of the heating heat exchanger to be adjacent to the heating heat exchanger. Generally, a temperature of air flowing at an immediately downstream air side of the heating heat exchanger is uniform. Therefore, air having an uniform temperature is blown separately to the vehicle right and left sides toward the foot portions of the driver and the front passenger. As a result, a temperature of air blown toward the foot portion of the driver may differ largely from a temperature of air blown toward the foot portion of the front passenger, thereby worsening heating feeling.
In view of the foregoing problems, it is an object of the present invention to improve mountability to a vehicle and heating feeling of a vehicle air conditioner in which a cooling :heat exchanger and a heating heat exchanger are disposed respectively in a substantially horizontal direction, and blown air flows through the heat exchangers in a substantially vertical direction.
According to the present invention, an air conditioner for a vehicle having a passenger compartment has a case, a cooling heat exchanger, a heating heat exchanger, a temperature adjusting member, an air mode switching door and a foot duct. The case forms an air passage through which air flows, and has a face opening, a defroster opening and a foot opening through which air is blown into the passenger compartment. The cooling heat exchanger is disposed in a substantially horizontal direction in the case for cooling air. The heating heat exchanger is disposed in a substantially horizontal direction in the case at an upper side of the cooling heat exchanger and at a lower side of the face, defroster and foot openings for heating air. The temperature adjusting member adjusts a temperature of air blown into the passenger compartment by adjusting an amount of the air heated by the heating heat exchanger. The air mode switching door opens and closes the face, defroster and foot openings. The foot duct is disposed at a vehicle front side of the case to communicate with the foot opening and extends downwardly from an upper portion of the case to a bottom portion of the case. Further, the foot duct has a foot outlet through which air is blown toward a foot portion of a passenger seated on a front seat in the passenger compartment at a lower portion thereof. Air flowing at an upper side of the heating heat exchanger in the case is introduced into the foot duct through the foot opening in a foot mode in which the foot opening is opened by the air mode switching door.
Since the foot duct is disposed at the vehicle front side of the case, a size of the air conditioner in the vehicle width direction is not increased by the foot duct. Therefore, a foot accommodating space of a driver and a front passenger in the passenger compartment is restricted from being reduced by the air conditioner. Thus, the air conditioner is mounted on the vehicle efficiently. Further, since the foot outlet is disposed at the lower portion of the foot duct, air is directly blown toward a toe of the passenger disposed below the instrumental panel at a vehicle front side. As a result, heating feeling is improved without providing an additional long foot duct extending from a vehicle rear portion of the case to a vehicle front portion of the case.
Preferably, the case is disposed at a substantially center of an instrumental panel in the passenger compartment in a vehicle width direction, and a blower unit for blowing air toward the case is disposed at a front passenger""s side to be shifted from the case in the vehicle width direction. As a result, a size of the air conditioner in a vehicle front-rear direction is reduced, and the air conditioner is more efficiently mounted on the vehicle.
More preferably, the foot outlet has first and second foot outlet portions respectively disposed in right and left side walls of the foot duct facing each other in the vehicle width direction. Warm air from the foot opening flows through the foot duct, and then is separated to vehicle right and left sides through the first and second foot outlet portions. Therefore, the warm air is well mixed before being separated to the vehicle right and left sides. As a result, a difference between a temperature of air blown toward the driver and a temperature of air blown toward the front passenger is reduced, thereby further improving heating-feeling.